FIELD EFFECT TRANSISTOR, DISPLAY ELEMENT, IMAGE DISPLAY DEVICE AND SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a field effect transistor which is capable of a high-speed operation and has high reliability.SOLUTION: A field effect transistor comprises: a base material; a protection layer; a gate insulation layer formed between the base material and the protection layer; a source electrode and a drain electrode which are formed so as to contact the gate insulation layer; a semiconductor layer which is formed at least between the source electrode and the drain electrode and contacts the gate insulation layer, the source electrode and the drain electrode; and a gate electrode which is formed on the opposite side to the semiconductor layer across the gate insulation layer and contacts the gate insulation layer. The protection layer contains a composite metal oxide at least containing Si and alkali earth metal.